The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingLuggage room light
Components
Removal
Disconnect cable from negative battery
terminal
Caution:
Wait at least 90 seconds after disconnecting the
cable from the negative (-) battery terminal to
prevent airbag and seat belt pretensioner activation.
Remove back door center garnish (see page
ed-59)
...
Pressure control solenoid "A" electrical (shift solenoid valve sl1)
Description
Shifting from 1st to o/d is performed in combination with the on and off
operation of the shift solenoid
valves sl1 and sl2, which are controlled by the ecm. If an open or short circuit
occurs in any of the shift
solenoid valves, the ecm controls the remaining normal shift soleno ...
Parking Support Brake function
(static objects)
If the sensors detect a static object, such as a wall, in the
traveling direction of the vehicle and the system determines
that a collision may occur due to the vehicle suddenly moving
forward due to an accidental accelerator pedal operation, the
vehicle moving the unintended direction due to the wr ...